State of Art in Prediction of Fluvial Sandbodies in Low Permeable Tyumen Formation of West Syberia

Abstract

Effective development of hard-to-recover reserves is one of the key activities of Russian oil companies. Great interest in this category of deposits is related to significant reserves. Prospective target for the development in Krasnoleninskoye field are deeply buried continental deposits of Tyumen formation which are related to the category of hard-to-recover reserves. Tyumen Formation is represented by interbedded sandstone, siltstone, shale, coal and characterized by low reservoir properties, average porosity and permeability are 12 % and 0.4 md, respectively. Despite numerous attempts to come to full-scale development of these deposits - and this has become possible only since the late 90's after the introduction of hydraulic fracturing technology, but there was no significant results. The main problem in this case is very complex geological structure, and if the problem of low permeability is solved by reservoir stimulation using hydraulic fracturing, the problem of spatial distribution prediction of the sandbodies is still actual, which in turn is a cause of low drilling success, flowrates and difficulties in effective waterflooding design. At the present an attempt solving the problem by drilling horizontal wells to enter maximum amount of sandbodies and their involvement in the development at the expense of a multistage hydraulic fracturing. This paper considers an example of the successful application of the engineering approach by integrating data from various lines of inquiry (seismic, geology and reservoir engineering, well testing) in order to forecast continental deposits of Tyumen formation and successful exploration drilling organization.